Earthworking machines, such as excavators, backhoes, front shovels, and the like, are used to perform a wide variety of tasks. For example, earthworking machines are used to dig foundations, install and maintain utilities, dig trenches, dredge waterways, perform landscaping operations, and accomplish many other jobs.
The extensive use of earthworking machines, and the associated expense of using them, has created a great need for technological improvements and innovations to make operations more efficient, more productive, less strenuous on human operators, and more accurate. For example, using terrain map data and position determining systems such as GPS, an operator of an earthworking machine may be provided with a display of the terrain being worked, the machine and earthworking implement as the work is performed, and changes being made to the terrain, all in real time. Examples of display technology being used by earthworking machines include U.S. Pat. No. 5,864,060 to Henderson et al., U.S. Pat. No. 5,438,771 to Sahm et al., U.S. Pat. No. 5,404,661 to Sahm et al., and U.S. Pat. No. 5,631,658 to Gudat et al.
However, a major problem associated with earthworking operations, and one that is not addressed by the above mentioned references, is the presence of already existing underground objects, such as utility lines, gas pipelines, and the like. Currently, an operator of an earthworking machine must rely on location marks, maps, and guesswork to avoid damaging underground objects. Often, as the operator of an earthworking machine approaches the estimated location of an underground object, the operator must stop and allow other workers to carefully hand dig further.
It is desired to be able to increase productivity and efficiency, yet minimize damage to underground objects without resorting to manual labor means, by providing the operator of an earthworking machine with an indication, preferably on a display, of the location of any known underground objects relative to the earthworking implement. It is also desired to provide an operator of an earthworking machine with a display of underground objects relative to the earthworking implement that compensates for errors introduced in determining the locations of the implement and the objects.
The present invention is directed to overcoming one or more of the problems as set forth above.